DE102017211878A1 - tool head - Google Patents

Abstract

A tool head having an axis of rotation, wherein at least one first tool and at least one second tool are arranged circumferentially on the tool head, and wherein the at least one first tool is an adjusting tool, which is arranged to be radially movable, whereby a radial position relative to the at least one second tool can be changed.

Description

The present invention relates to a tool head, a method for machining an inner surface of a cylinder and a use of a tool head.

The cylinders in question are, in particular, the cylinders of internal combustion engines. It is state of the art to provide the cylinder inner surfaces, in particular of aluminum crankcases, with a coating applied, for example by means of a thermal spraying method, wherein this coating process is preceded by an activation of the cylinder inner surface in order to ensure the adhesion of the coating. In this context, it is known to roughen the cylinder surfaces before coating by means of high-pressure water jet technology. However, this process is highly dependent on the casting quality. In addition, the process-related investment, energy and resource use is problematic. A more recent approach consists in a mechanical processing of the cylinder wall before coating, in particular, for example, in an introduction of grooves, which may possibly be deformed in a subsequent forming or deformation step so that undercuts are formed, which should allow a clinging with the coating. Thus, although some of the aforementioned disadvantages may be eliminated under certain circumstances. However, the difficulty is to ensure that the coating will last reliably over the entire service life.

It is therefore an object of the present invention to provide a tool head, a method for processing an inner surface of a cylinder and a use of a tool head, which eliminate the aforementioned disadvantages and are easy and inexpensive to implement.

This object is achieved by a tool head according to claim 1, by a method according to claim 9 and by a use according to claim 13. Further advantages and features will become apparent from the dependent claims and the description and the accompanying figures.

According to the invention, at least one first tool and at least one second tool are circumferentially arranged on a tool head, which has a rotation axis, wherein the at least one first tool is an adjustment tool, which is arranged radially movable, whereby a radial position relative to the at least one second tool can be changed or adjusted. In particular, an engagement or machining order or depth, or an action force, such as a forming or indenting force, of the adjustment tool with respect to a surface to be machined can be adjusted. This is particularly advantageous in the machining of cylinders of internal combustion engines, since thus, taking into account the feed direction or the tools used, the processing of a cylinder wall / cylindrical surface can be controlled. For example, when driving into a cylinder, the adjustment tool can be adjusted so that it works on the cylinder surface, while it is set out when driving out of the cylinder so that it does not work the cylinder surface or less deep or strong or vice versa, etc. When driving out acts then primarily, for example, the at least one second tool. Thus, at least two-stage editing with only one tool head is possible.

Conveniently, the or the first and second tools are rotatably arranged in the tool head. The tools can be mounted via a rolling bearing. According to a preferred embodiment, they are only slidably mounted.

According to one embodiment, the first tool is provided with an adjusting unit which is designed to actively move or displace the at least one adjusting tool in the radial direction, wherein this adjusting unit can be designed to be electrically, hydraulically and / or pneumatically.

According to a preferred embodiment, the adjusting tool is supported towards the axis of rotation on a cone and is axially movably arranged such that depending on a feed direction of the tool head, the radial orientation (to each other) can be adjusted. The adjusting tool is supported in the radial direction or towards the axis of rotation, that is to say on the cone, as it were viewed inwardly in the direction of the axis of rotation, wherein the at least one adjusting tool is arranged to be movable in the axial direction. This makes it possible to design the adjustment constructively very simple, since ultimately on the axial mobility and in that the at least one adjusting tool can be supported on the cone, indirectly, the radial adjustment is possible. According to a preferred embodiment, the at least one adjusting tool is arranged in the axial direction with clearance, for example in a correspondingly formed (bearing) cage or generally has an adjustment path, whereby the radial position can be adjusted depending on a feed direction of the tool head. The size of the adjustment depends on the dimensions of the tool head and is according to some embodiments in the range of a few millimeters. Conveniently, therefore, the at least one adjusting tool is mounted in the axial direction with clearance on the cone, whereby the depth of engagement, for example relative to a cylinder wall to be machined, adjusted relative to the at least one second tool, in particular, depending on the feed direction of the tool, virtually automatically changed can be.

For machining the cylinder, the tool head according to an embodiment, expediently connected or driven via a machine tool or a machining center, etc., set in rotation and retracted into the respective cylinder. Preferred speeds are in a range of preferably 500 to 1500 1 / min. Advantageously, since the tools are rotatably arranged or mounted in the tool head, they are automatically set into rotary motion by the contact with the cylinder wall. Appropriately, therefore, can be dispensed with a separate drive. The great advantage consists in the fact that, due to the play-related mounting of the at least one adjusting tool, an automatic realignment of the adjusting tool in the tool head also takes place, depending on a feed direction of the tool head. The fact that the adjusting tool is supported on the cone, however, not only an axial repositioning is achieved, but also a radial, which means that the adjusting tool, depending on the configuration or orientation of the cone, automatically moved in or out without this another drive or the like would be necessary. This approach enables the realization of an extremely robust and simply designed tool head.

According to one embodiment, a radial position or position of the at least one second tool is defined. Preferably, the axial and the radial position are fixed. In particular, therefore, the at least one roughening tool is firmly mounted, wherein the term "fixed" implies no freedom from play. It may well be game available, but which z. B. mainly the, in particular rotatable, arrangement is used, and not an axial or radial adjustment. Alternatively, both a radial and an axial mobility can be provided, whereby a radial adjustment of the at least one second tool is made possible.

According to one embodiment, the tool head comprises an upper and a lower base plate, between which a conical base body is arranged, in or at which the arrangement and mounting of the tools takes place. Alternatively, the aforementioned basic body may be surrounded by an additional bearing ring or cage, which additionally or alternatively serves the arrangement and / or mounting of the tools. Further alternatively, the bearing of the tools also, at least partially carried on the upper and the lower base plate, wherein the upper base plate expediently has a suitable connection area, for arranging the tool on, for example, a tool spindle. The basic structure of the tool is not limited to the aforementioned variants, but, in particular due to the effective basic concept, possible in many ways.

According to a preferred embodiment, the adjusting tool is a forming tool, wherein the second tool is a roughening tool. Particularly preferred are a plurality of forming tools, such as 5-10, and a plurality of roughening tools in the same number, circumferentially and alternately arranged or provided on the tool head. According to one embodiment, the tools have a substantially conical body or tool body, which is formed congruent to the aforementioned cone of the tool head. In particular, the main body of the at least one second tool, that is to say preferably the roughening tool, is also cylindrical in one embodiment, as a result of which the production costs can be reduced. Over the length of the conical or cylindrical tool body of the tools, if necessary, the aforementioned game can be adjusted very easily, so that the tool head or a corresponding bearing section, bearing ring or (bearing) cage of the tool head, in or on which the tools are arranged, otherwise further adjustments are not required. A length of the tool body is in preferred embodiments about 5 to 30 mm, more preferably about 10 to 20 mm. Typical diameters are about 5 to 20 mm, preferably about 8 to 15 mm.

The advantages of such a tool head are particularly evident in connection with the activation of cylinder running surfaces / inner surfaces for subsequent coating, for example by means of thermal spraying methods. As mentioned above, it is known to introduce a structure, for example in the form of grooves or webs, to activate the cylinder inner surface before the subsequent (thermal) coating by mechanical processing. Preferably, by means of the tool head or its forming tools, the webs can be deformed in such a way that undercuts are formed. In other words, the grooves have an approximately dovetail shape in cross-section after the forming. In order to further improve the attachment or the clamping of the subsequent coating, the roughening tools are provided, which structure or roughen the ridges and, in addition to the macro-macro-closure, which is formed by the undercuts, allow a microforming connection, as it were. By now the or the Forming tools are radially adjustable, for example, when moving in a reshaping of the webs, while the exit from the cylinder, characterized in that the forming tools go back by changing the feed direction, a structuring of the surface by means of the roughening done. The processing order can be easily adjusted by the orientation of the conical body of the tools, etc. (see, for example, upward or downward tapering, etc.).

According to one embodiment, the first and the second tool have engagement regions, wherein the engagement regions are preferably cylindrical. The intervention areas are in particular those areas of the tools, via which the actual processing takes place, which thus z. B. are provided for contact with the surface to be machined. In particular, the cylindrical shape allows exact positioning and alignment of the engagement areas with each other.

According to one embodiment, the engagement regions in each case form effective diameters, wherein due to the radial positionability, an effective diameter of the first tool can both exceed and fall below a working diameter of the second tool, in particular by providing a suitable undersize or oversize. The values are depending on the embodiment z. In a range of about 0.01 to 1 mm, preferably in a range of about 0.02 to 0.5 mm. A diameter of the engagement region of the forming tool is according to one embodiment, for. B. 0.1 to 0.3 mm smaller than the diameter of the roughening tool.

The effective diameters are according to various embodiments, in particular for the processing of crankcases / cylinders of car engines, at about 70 to 100 mm. In motorcycle engines, the diameters can be significantly smaller or in the field of commercial vehicle technology or in large engines also significantly larger. However, the basic structure does not change.

According to one embodiment, one or the engagement region of the at least one second tool, in particular of the roughening tool, is coated or formed by a coating or has elevations, projections, grooves, grooves and / or the like. Preferably, the engagement region of the roughening tool is at least partially diamond or particle coated. Preferred average grain sizes in the diamond coating range from D91 to D301.

One or the engagement region of the first tool or forming tool has a substantially smooth or even surface. Preferably, the engagement areas of the forming tools, as mentioned, are also cylindrical.

Diameters of the engagement regions are in preferred embodiments in a range of about 5 to 25 mm.

Alternatively, the engagement areas are formed directly on the basic bodies or by these. If the base bodies are of conical design, these are expediently inclined to the axis of rotation of the tool head in such a way that the circumferential surfaces on which the engagement regions are formed are approximately parallel to the surfaces to be machined.

Preferably, the first and / or the second tool made of hard metal. Advantageously, thus extremely high tool life can be realized.

According to one embodiment, the tool head comprises a drive unit for driving one or more tools.

According to one embodiment, the tool head comprises a cooling device. In particular, the cooling device is designed to cool the circumferentially arranged tools. Such a cooling device is advantageous, in particular when using coated roughening tools, such as, for example, diamond-coated roughening tools, since this ensures that the coating, for example in the form of the diamonds, is held on the corresponding tool. Typical coolant flows operate at a pressure of up to 80 bar. According to one embodiment, the coolant flow may be used to drive the tools. As mentioned in the introduction, the rotatably arranged or mounted tools are, so to speak, indirectly driven by the rotation of the tool head relative to the stationary cylinder wall, according to one embodiment. This results in driving into the cylinder in a very strong speed gradient. In this respect, a drive or a certain pre-drive, which offset the tools at least in a certain rotational movement, has shown to be extremely advantageous with regard to the wear behavior.

• - Bereitstellen eines Werkzeugkopfes, welcher eine Rotationsachse und eine Vielzahl von umfänglich angeordneten Werkzeugen aufweist;
• - Bevorzugt Drehen des Werkzeugkopfes und Einfahren in einen Zylinder zum Bearbeiten einer Innenwand des Zylinders;
• - Verändern einer radialen Position zumindest eines Werkzeugs relativ zu dem oder den anderen Werkzeugen zum Einstellen einer Bearbeitungsreihenfolge.

Furthermore, the invention relates to a method for processing an inner surface of a cylinder, in particular of a cylinder of an internal combustion engine, comprising the steps:

• - Providing a tool head having a rotation axis and a plurality of circumferentially arranged tools;
• - Preferably rotating the tool head and retracting into a cylinder for machining an inner wall of the cylinder;
• - Changing a radial position of at least one tool relative to the one or other tools for setting a processing order.

The at least one aforementioned tool, which changes its radial position, is expediently an adjusting tool, in particular an adjusting tool according to the invention.

• - Verringern eines Wirkdurchmessers des oder der Umformwerkzeuge beim Ausfahren aus dem Zylinder.

Preferably, at least one tool is a roughening tool and at least one tool is a forming tool, the method comprising the step:

• - Reducing an effective diameter of the forming or the forming tools when extending out of the cylinder.

Advantageously, this can be achieved by structuring or roughening the surface of the cylinder when moving out of the tool head from the cylinder. Accordingly, the method is advantageously performed so that when retracting only or at least predominantly takes place a transformation. Conveniently, the adjusting tools are arranged with axial clearance in the tool head and are supported on an inner cone, as has already been described above. Conveniently, in this embodiment, the cone is oriented in such a way that it reduces downwards with respect to a vertical axis or cylinder axis.

• - Vergrößern eines Wirkdurchmessers des oder der Aufrauwerkzeuge beim Ausfahren.

Alternatively and / or additionally, the method comprises the step:

• - Increasing an effective diameter of the or Aufrauwerkzeuge when extending.

This has the same effect as previously described, namely namely that when moving out of the tool head out of the cylinder, the roughening can take place with advantage.

• - Bearbeiten der Zylinderwand zum Einbringen einer Oberflächenstruktur;
• - Beschichten der Innenwand des Zylinders nach dem Bearbeiten mit dem Werkzeugkopf.

According to one embodiment, the method comprises the steps:

• - Processing the cylinder wall for introducing a surface structure;
• - Coating the inner wall of the cylinder after machining with the tool head.

The surface structure comprises, as already indicated, for example, a plurality of grooves or grooves, preferably introduced mechanically. The structuring can alternatively or additionally but also be done by means of suitable laser technology. Preferably, the thermal spraying is used for coating, wherein, for example, the so-called flame spraying or plasma spraying or arc wire spraying are used. In this case, powder and / or wire particles with high thermal and kinetic energy are thrown or sprayed onto the surface of the substrate to be coated. Coating takes place after machining the cylinder wall with the tool head.

The invention is further directed to the use of a tool head according to the invention for producing an internal combustion engine or a crankcase.

The advantages and features mentioned in connection with the tool head apply analogously and correspondingly also for the method and for the use as well as vice versa and with each other.

Further advantages and features will become apparent from the following description of preferred embodiments of a tool head with reference to the accompanying figures.

• 1: eine teilweise Draufsicht auf einen Werkzeugkopf entlang einer Rotationsachse gesehen sowie eine Detailansicht zur Veranschaulichung der unterschiedlichen Wirkdurchmesser der Werkzeuge;
• 2: eine schematische Schnittdarstellung eines Werkzeugkopfes zur Verdeutlichung der Funktionalität des Verstellwerkzeugs.

Show it:

• 1 a partial plan view of a tool head along a rotation axis as well as a detailed view for illustrating the different effective diameters of the tools;
• 2 : A schematic sectional view of a tool head to illustrate the functionality of the adjusting tool.

1 shows in its left half of the picture along a rotation axis R seen a tool head 10 with a plurality of circumferentially arranged first and second tools 20 respectively. 22 , wherein alternately each a roughening tool 22 and a forming tool 24 can be seen. Dashed lines show a cylinder wall 50 , which by means of the tool head 10 is processed. In the right half of the picture are sketchy a roughening tool 22 as well as a forming tool 24 with their respective intervention areas 23 respectively. 25 showing that it is clear that the engagement area 23 of the roughening tool 22 the intervention area 25 of the forming tool 24 around a radial offset d surmounted. In other words, an effective diameter D22 of the roughening tool 22 greater than one effective diameter D24 of the forming tool 24 , For better orientation is still with the reference numeral R the course of the axis of rotation sketched. The oversize or the offset d is z. B. in a range of about 0.01 to 1 mm. This results, for example, by a radial displacement of the forming tool 24 to the axis of rotation R out.

The 2 shows in its left half in half a tool head 10 comprising an upper and a lower base plate 13 , between which a basic body 12 is arranged, this basic body 12 has a cone shape. With the reference number 14 is a bearing section or a bearing ring 14 outlined, inter alia, the storage of the first and second tools 20 . 22 serves. Basically, the configuration comprising the main body 12 or the base plates 13 as well as the storage section 14 merely to be understood as an example. The arrangement or storage of the tools 22 and 20 respectively. 24 can be done in many ways. In particular, the axial mobility or the axial play along the axis of rotation R be solved constructively in different ways. The 2 serves in particular to the operation of the first tool or adjusting tool 20 , here a forming tool 24 to visualize in the right half of the picture. A roughening tool 22 is here along the axis of rotation R fixed formed. Will the tool head 10 along the feed direction V1 (in the middle image area) directed downward, for example, when driving in the tool head 10 in a cylinder, this causes the adjustment tool 20 , in particular the forming tool 24 as by the arrow P outlined, is pressed radially outwards, as it is virtually along the axis of rotation R on the conical body 12 moves upward and is thereby pressed outwards. For this purpose, the adjustment tool 20 in turn a conical basic form. When moving out of the cylinder, sketched in the right half of the picture (see reference numeral V2 ) takes place, automatically (or by the provision of an adjustment), a realignment of the adjustment 20 or of the forming tool 24 so now an intervention area 23 of the roughening tool 22 can work. The automatic alignment can in particular via a play-bearing storage of the corresponding tool base 26 respectively. The oversize is preferably set as shown in the right half of FIG 1 outlined. This configuration can ensure that, at least in this embodiment, as the last processing step, when driving out of the cylinder a roughening of the cylinder inner surface or the webs takes place.

LIST OF REFERENCE NUMBERS

10

tool head

12

Basic body, cone

14

Bearing section, bearing ring

20

first tool, adjusting tool

22

second tool, roughening tool

23

Engagement area roughening tool

24

forming tool

25

Engagement area forming tool

26

tool body

D22

Working diameter roughening tool (second tool)

D24

Effective diameter forming tool (first tool)

50

cylinder wall

d

radial offset

V, V1, V2

feed directions

R

axis of rotation

P

arrow

Claims (13)

Tool head (10), which has an axis of rotation (R), wherein circumferentially on the tool head (10) at least a first tool (20) and at least one second tool (22) are arranged, and wherein the at least one first tool (20) is an adjustment tool which is arranged to be radially movable, whereby a radial position relative to the at least one second tool (22) can be changed. Tool head (10) after Claim 1 , wherein the adjusting tool (20) to the rotation axis (R) towards a cone (12) is supported and axially movable so that depending on a feed direction (V) of the tool head (10), the radial position can be adjusted. Tool head (10) after Claim 1 or 2 wherein a radial position of the at least one second tool (22) is fixed. A tool head (10) according to any one of the preceding claims, wherein the adjustment tool (20) is a forming tool (24), and wherein the at least one second tool (22) is a roughening tool. Tool head (10) according to one of the preceding claims, wherein the first and second tools (20; 22) have engagement portions (23; 25), and wherein the engagement portions (23; 25) are cylindrical. Tool head according to one of the preceding claims, wherein the at least one second tool (22) has a cylindrical base body. Tool head (10) according to one of the preceding claims, wherein the or an engagement region (23) of the at least one second tool (22) is coated, in particular diamond-coated, is. The tool head (10) of any one of the preceding claims, wherein the or an engagement portion (25) of the at least one first tool (20) has a smooth or planar surface. Method for processing an inner surface of a cylinder, in particular a cylinder of an internal combustion engine, comprising the steps: - Providing a tool head (10) having a rotation axis (R) and a plurality of circumferentially arranged tools (20; 22); - Retracting into a cylinder for machining an inner wall (50) of the cylinder; - Changing a radial position of at least one tool (20) relative to the one or more other tools (22) for setting a processing order. Method according to Claim 9 wherein at least one tool is a roughening tool (22) and at least one tool is a forming tool (24), comprising the step of: - reducing an effective diameter (D24) of the forming tool (s) (24) during extension. Method according to one of Claims 9 - 10 wherein at least one tool is a roughening tool (22) and at least one tool is a forming tool (24), comprising the step of: - increasing an effective diameter (D22) of the roughening tool (22) during extension. Method according to one of Claims 9 - 11 comprising the steps of: - working the inner wall (50) of the cylinder for introducing a surface structure, in particular of grooves; - Coating the inner wall (50) of the cylinder after machining with the tool head (10). Use of a tool head (10) according to one of Claims 1 - 8th for producing an internal combustion engine.

Images